Effect of Process Parameters on the Microstructural Characteristics and Mechanical Properties of AZ80A Mg Alloy During Friction Stir Welding

In this paper, the influence of process parameters on microstructural characteristics & mechanical properties of AZ80A Mg alloy during friction stir welding (FSW) are investigated in a detailed manner. The tensile fracture surfaces obtained from successfully fabricated joints are subjected to tensile tests and microstructural investigations were done using scanning electron microscope. From the experimental results, the joints produced under a 5 kN axial force value at 1000 rpm and at a feed rate of 1.5 mm/min were found to exhibit superior mechanical properties and metallurgically defect free weldments when compared with other joints. The chemical compositions of these defect free joints were analyzed using energy dispersive spectrometry. Moreover, ideal level of heat generation, uniform flow of the plasticized material and formation of fine grain structure with uniform distribution in the FSW zone were found to be the main reasons for these superior mechanical properties and flawless joints.